A power supply system for a vehicle is provided. The power supply system includes a high-voltage battery pack having a plurality of batteries, a primary isolated converter connected to the high-voltage battery pack, and a plurality of distributed isolated converters, each of the plurality of distributed isolated converters being connected to one of the plurality of batteries. Each of the distributed isolated converters includes a primary stage configured to receive power from one of the plurality of batteries and an isolated stage configured to provide power to a low-voltage bus. The bias signals configured to control the operation of each of the plurality of distributed isolated converters are powered by the connected one of the plurality of batteries and activated based on an enable signal provided by the primary isolated converter.